A Lithogeochemical Study of the Metal Contents of the Upper Cretaceous Oil in the Pasquia Hills, East-Central Saskatchewan

Murray C. Rogers 1

Information from this publication may be used if credit is given. It is recommended that reference to this publication be made in the following form: Rogers, M.C. (2016): A lithogeochemical study of the metal contents of the Upper Cretaceous oil shales in the Pasquia Hills, east-central Saskatchewan; in Summary of Investigations 2016, Volume 2, Saskatchewan Geological Survey, Saskatchewan Ministry of the Economy, Miscellaneous Report 2016-4.2, Paper A-1, 17p. This paper is associated with the following publication: Rogers, M.C. (2016): Geochemical analyses of drillhole core from Cretaceous Upper Colorado Group oil in east-central Saskatchewan (NTS 63E/03, /04); Saskatchewan Ministry of the Economy, Saskatchewan Geological Survey, Data File 41.

Abstract The results of a multi-element geochemical study are reported from the selective sampling of core from five drillholes that intersected Cretaceous oil shales on the northwest flank of the Pasquia Hills in east-central Saskatchewan. Black shales, particularly organic-rich shales, commonly have anomalous—and in some cases potentially economic—metal contents. Upper Cretaceous oil shales of the Niobrara (First White Speckled Shale) and Favel (Second White Specks) formations occur at shallow depth, in subcrop and as local outcrop, in the Pasquia Hills, and extend in subcrop and at depth through central Saskatchewan. Although the oil shales in the Pasquia Hills have been extensively drilled and tested for their kerogen (oil) potential since the 1960s, there is no public record that they have been examined in any detail for their metal contents. The core from several recent drillholes from this region is stored in Regina at the Subsurface Geological Laboratory of the Ministry of the Economy. Five of these holes from the northwest flank of the Pasquia Hills were selected for sampling. The oil shale sections in these holes average about 30 m in thickness. Four representative one-metre chip samples of the core were taken from each hole, approximately equidistant through each core section. The samples were then sent for multi-element analysis by inductively coupled plasma–optical emission spectroscopy (ICP-OES) and fire assay (Au, Pt, Pd)–ICP-OES. The United States Geological Survey’s (USGS) standard for metalliferous black shales was used as a basis to interpret the results of the multi-element analyses. The gold values (with one exception) are highly anomalous, with 19 of the 20 samples exceeding the USGS standard of 5.6 ppb. The arithmetic mean (average) value for all 20 samples was 45 ppb (eight times (8X) greater than the USGS standard) and the high value was 129 ppb (23X). Based on the albeit limited number of drillholes and samples, the mean gold values display a general westward increase, with the highest mean value of 103 ppb Au in the most western drillhole. A hydrothermal source to the west is inferred for the anomalous gold. Other metalliferous elements include Ag, Zn, Se, P2O5, Sr and V. Based on the clearly anomalous but unspectacular level of values and the consistent distribution of these metals both within the individual drillholes and between the drillholes, their source has been attributed to absorption of metals by organic matter from seawater and further concentration in during diagenesis in the reduced, anoxic sediments. Keywords: oil shale, Upper Cretaceous, metals, geochemistry, gold, Pasquia Hills, east-central Saskatchewan

1. Introduction The purpose of this lithogeochemical study was to determine the metal contents of the Upper Cretaceous oil shales on a portion of the northwest flank of the Pasquia Hills area of east-central Saskatchewan (Figure 1). Macauley (1984) defines oil shale as an organic-rich, fine-grained, dark brown to black that contains kerogen from which liquid hydrocarbons can be extracted by heating. Black shales, particularly organic-rich shales, often have anomalous, and in some cases potentially economic, metal contents.

1 Saskatchewan Ministry of the Economy, Saskatchewan Geological Survey, 1000-2103 11th Avenue, Regina, SK S4P 3Z8 Although the Saskatchewan Ministry of the Economy has exercised all reasonable care in the compilation, interpretation and production of this product, it is not possible to ensure total accuracy, and all persons who rely on the information contained herein do so at their own risk. The Saskatchewan Ministry of the Economy and the Government of Saskatchewan do not accept liability for any errors, omissions or inaccuracies that may be included in, or derived from, this product.

Saskatchewan Geological Survey 1 Summary of Investigations 2016, Volume 2

Figure 1 – Location of the project area on the northwest flank of the Pasquia Hills, east-central Saskatchewan (geological and urban municipality base map is from the Geological Atlas of Saskatchewan, Saskatchewan Ministry of the Economy website) showing the regional subcrop of the oil shale formations (Kws) and estimated projection of the Tabbernor Fault Zone (TFZ).

The Pasquia Hills form the northwestern extent of the Manitoba Escarpment. The area to the east of the town of Arborfield (Figure 2) was selected for this study because the oil shales are near the surface here and, since the 1960s, have been the focus of a number of drill programs because of their kerogen content. The core from several drillholes from recent programs is available for examination and study at the Saskatchewan Ministry of the Economy’s Subsurface Geological Laboratory (SGL) in Regina. Five of these drillholes (Figure 2) from a Questerre Energy Corporation (Questerre) drill program on the northwest flank of the Pasquia Hills in 2012 were selected for core sampling and multi-element analysis. The oil shales in this area, which generally contain ≥5% total organic carbon (TOC), have average cored sections of about 30 m.

Figure 2 – Locations of the five Questerre Arborfield drillholes selected for the core sampling program, with the local interpreted noted (base map is from the Geological Atlas of Saskatchewan, Saskatchewan Ministry of the Economy website). Locations of other drillholes with core available at the SGL are also indicated (green dots) but not labelled.

The complete geochemical results, as well as information on the drillhole and sample locations, are tabulated in Data File 41, a separate publication associated with this paper.

Saskatchewan Geological Survey 2 Summary of Investigations 2016, Volume 2

2. Deposit Model for Metalliferous Black Shales Pyritic black shales occur throughout the world and are potential sources of a wide variety of metals that may include Ni, Mo, As, Zn, Pb, Cu, Cd, Co, Cr, U, V, Se, Ag, Au, platinum group elements (PGE), rare metals, and rare earth elements (REE)+(Y,Sc) in addition to oil and industrial minerals. They typically have high organic carbon contents, to which the metal contents are commonly correlated. The stratabound to stratiform mineralization tends to be very large, low grade and regionally extensive, but with rare, notable high-grade exceptions such as in southern China. The black shales are commonly related to periods of widespread oceanic anoxia. Deposits and districts that have been and are being mined include Talvivaara, Finland; Yangtze Platform, southern China; and the Alum Shale, Sweden. There are two principal genetic theories for their formation: 1) hydrothermal metal exhalation along basin margin faults with the deposition of metals in reduced, anoxic sediments; and 2) absorption of metals from seawater onto organic matter, followed by concentration in sulphides and other minerals in anoxic sediments during diagenesis under euxinic conditions.

a) World Examples The Talvivaara Ni-Cu-Zn deposit in Finland is a Precambrian example of mineralized, metamorphosed, sulphidic black shale (Loukola-Ruskeeniemi and Heino, 1996). It is hosted by the Paleoproterozoic Kainuu schist belt, which consists mainly of metasedimentary rocks with discontinuous serpentinites. The orebody, which is mined by open pit and bio-heap-leach methods, contains 300 million tonnes grading 0.26% Ni, 0.14% Cu and 0.53% Zn, with 100 ppm Mo, 630 ppm V and 7% organic C. The deposit is up to 330 m thick, although this has been modified by tectonic thickening. Dominant sulphides, comprising pyrrhotite and pyrite with minor chalcopyrite, sphalerite, alabandite and pentlandite, occur as fine disseminations, and as coarser grains in quartz-sulphide veins. Loukola-Ruskeeniemi and Heino (1996) attribute the mineralization to hydrothermal activity in a rift environment with deposition in organic-rich anoxic sediments. Early Cambrian, black shale–hosted Mo-Ni and V mineralization of the Yangtze Platform, China occurs as a thin (a few centimetres) sulphide horizon with a strike length of about 1600 km (Lehmann et al., 2016). Mining occurs intermittently along this extent. The mineralization consists of Mo (~4%) and Ni (~2%), with about 600 ppm V and highly anomalous Zn, As, Se, Au, Ag, PGE and U. Metal enrichment is attributed to an environment of high biological activity, a very low clastic sediment accumulation rate, and a low rate of organic matter deposition in a stratified oxic- suboxic-euxinic basin, with the bottom water/sediment interface scavenging metals under euxinic conditions.

The Alum Shale in Sweden has been mined periodically for centuries for alum [KAl(SO4)2-12H2O], oil and uranium (Large, 2012). It is a Cambrian to Lower Ordovician, organic-rich, pyritic shale unit that is 20 to 60 m thick, within black shales that are over 200 m thick. At the Viken project, an NI 43-101–compliant Inferred Resource of 3.019 billion tonnes grading 172 ppm U3O8, 335 ppm Ni, 120 ppm Cu and 421 ppm Zn has been defined (Continental Precious Minerals Inc., 2014). The deposit was also reported to contain significant concentrations of molybdenum and vanadium. The Nick property in Yukon bears similarities to the southern China deposits (Hulbert et al., 1992). A thin layer (~3 cm) of stratiform Ni-Zn-PGE sulphide mineralization was deposited over the entire Devonian Nick basin, an area 2 over 80 km . The mineralization consists of pyrite, vaesite [NiS2] and sphalerite, with an average historical grade of 5.3% Ni, 0.73% Zn and 770 ppb PGE+Au, and anomalous Re, Se, As, Mo, P, Ba and U. The mineralization is attributed to syndepositional introduction of metals by fault-controlled, organic-rich, low-temperature, hydrothermal fluids into a euxinic basin. The Carboniferous–Permian Lisburne Group of northern Alaska contains metalliferous black shales within phosphorite sections that have a mean content of 7.53% organic carbon with average metal values from 17 shale sections of 144 ppm Cu, 1112 ppm Zn, 52.5 ppm Cd, 283 ppm Ni, 13.4 ppm Ag, 56.5 ppm Mo, 2.1 ppm Tl, 759 ppm Cr and 881 ppm V (Dumoulin et al., 2011). High metal concentrations correlate positively with the organic carbon content. Predominantly seawater and biogenic sources are indicated for Cr, V, Mo, Zn, Cd, Ni and Cu. An additional hydrothermal contribution is indicated for Zn, Cd, Ag and Tl.

Saskatchewan Geological Survey 3 Summary of Investigations 2016, Volume 2

b) Geochemical Standard for Metalliferous Black Shales A general definition for a black shale is provided by Huyck (1990). It is a dark-coloured (grey or black), fine-grained (silt sized or finer), laminated sedimentary rock that generally is argillaceous and contains appreciable organic carbon (>0.5 weight percent (wt. %)). Metalliferous black shale is defined as black shale that is enriched in any given metal by a factor of two times (2X)—or 1X for Be, Co, Mo, U—relative to the United States Geological Survey (USGS) Black Shale Standard SDO-1 (Huyck, 1990). The USGS Black Shale Standard SDO-1 metalliferous values (all in ppm) are: Ag 0.262 Cd 10 Hf 9.4 Pb 55.8 Tl 16.6 As 137 Cl 232 Hg 4.4 Rb 252 U 48.8 Au 0.0056 Co 46.8 In 0.2 Sb 8.9 V 320 (5.6 ppb) Cr 132.8 Li 56.2 Sc 26.4 W 6.6 B 256 Cs 13.8 Mn 649 Se 9.8 Y 81.2 Ba 694 Cu 120.4 Mo 134 Sn 58 Zn 128.2 Be 3.3 F 0.07 Nb 22.8 Sr 150.2 Zr 330 Bi 10 Ga 33.6 Ni 199 Ta 2.2 Br 10 Ge 2.6 P 960 Th 21

REE: La 77 Gd 13 Yb 6.8 Ce 158.6 Tb 2.4 Lu 1.04 Pr 19.8 Dy 11.4 total rare earth 473.3 Nd 73.2 Ho 2.4 oxides (TREO) + Y Sm 15.4 Er 7.2 Eu 3.2 Tm 0.9

Platinum group elements were not included in this standard, but a gold equivalent was adopted. This standard is used as a benchmark for this study.

3. Geology of the Cretaceous Oil Shales in Saskatchewan Although regional geological surveys had been carried out by previous workers, Beck (1974) was the first to systematically map the Pasquia Hills and examine the economic potential of the underlying rocks. In addition to the oil potential, the oil shales in this area also contain ammonium sulphate and have been examined as a source of cement rock due to their and kerogen contents. Beck (1974) divided these Upper Colorado Group shales into the Vermillion River (Boyne and Morden members) and Favel formations. The Boyne Member and the Favel Formation are the oil shale units. They are macroscopically indistinguishable, and are separated by the Morden Member, which is a dark grey shale. Later workers further refined the stratigraphic sequence and nomenclature in this region (Macauley, 1984; Schröder- Adams et al., 1999; Bloch et al., 2002; Christopher and Yurkowski, 2005; Christopher et al., 2006). Use of the term Boyne Member of the Vermillion River Formation was replaced by the more regional Niobrara Formation, which was informally subdivided into the lower calcareous shale and the upper chalky members. The Niobrara Formation is also referred to as the First White Speckled Shale (Figure 3), and is of Coniacian–Santonian age (89.8 to 83.6 Ma). The Favel Formation was subdivided into the Keld and Assiniboine members, is correlative to the west with the Second White Specks Formation, and is of lower Turonian age (93.9 to 91.9 Ma). The older Keld Member consists of bituminous limestone and marlstone, and the younger Assiniboine Member consists of bituminous limestone and calcareous black shale. The non-calcareous, dark grey shale of the Morden Formation separates the Niobrara and Favel formations and is of upper Turonian age (91.9 to 89.8 Ma). Farther west, the term Morden Formation is replaced in regional use by Carlile Formation. Christopher et al. (2006) consider the Niobrara (Boyne)-Morden pair to be a sedimentological and stratigraphic repetition of the underlying Favel–Belle Fourche sequence.

Saskatchewan Geological Survey 4 Summary of Investigations 2016, Volume 2

Figure 3 – The stratigraphic columns for the Cretaceous Period in west-central and east- central Saskatchewan (derived from the Stratigraphic Correlation Chart, Saskatchewan Ministry of the Economy website, http://www.economy.gov.sk.ca/ StratigraphicCorrelationChart), illustrating the stratigraphic setting of the Upper Colorado Group formations described in this study (bracketed by the thick black lines).

Macauley (1984), Schröder-Adams et al. (1999), Bloch et al. (2002), Christopher and Yurkowski (2005) and Christopher et al. (2006) described the two oil shale formations as follows: both units consist of medium to dark grey to brownish grey to black calcareous shale, with variable white speckling from calcareous foraminiferal and coccolithic planktonic debris, which accounts for the First White Speckled and Second White Specks nomenclature farther west. Total organic carbon content in the oil shales is up to 10% over significant thicknesses and locally higher. These units are macroscopically indistinguishable but can be distinguished by micropaleontology. The shales are finely laminated to fissile with a decrease in fissility as the carbonate content increases. The two oil shale formations can be traced across the Prairie provinces but are thin in central Saskatchewan. The Niobrara Formation ranges from 30 to 45 m in thickness along the Manitoba Escarpment (Macauley, 1984), thins to 15 to 18 m in central Saskatchewan where it directly overlies the Favel Formation because the Morden (Carlile) Formation is missing, and thickens again to 35 to 60 m in Alberta. The Favel Formation is 30 to 40 m thick along the Escarpment, thins to a few metres in central Saskatchewan, and thickens again to 35 to 60 m in Alberta (Macauley, 1984).

The oil shales in the Pasquia Hills are immature, with Tmax values in the range of 405° to 425°C (Macauley, 1984). Immaturity is also indicated in plots of hydrogen vs oxygen indices (Macauley, 1984). The kerogen is represented by an admixture of Type II and Type III kerogens. Bloch et al. (2002) describe the oil shales as consisting of bioclastic detritus (calcite) and altered volcanic ash (smectite, mixed-layer illite-smectite, clinoptilolite, a zeolite group mineral, chert) with minor amounts of quartz, gypsum, pyrite and other minerals. The occurrence of abundant authigenic clinoptilolite and thin bedded cherts, in association with multiple bentonite beds (including the basin-wide X-bentonite), indicates that the alteration of volcanic ash may account for much of the silicate mineral assemblage in these formations. The abundance of organic matter promoted sulphate reduction, resulting in the formation of up to 7% pyrite, primarily as framboids. Recent weathering has oxidized pyrite, which by interaction with calcite has yielded gypsum.

Saskatchewan Geological Survey 5 Summary of Investigations 2016, Volume 2

The Second White Specks (Favel) Formation is interpreted to have been deposited during a maximum sea level of the Western Interior Seaway (Bloch et al., 1999), when warm seawater of normal salinity entered the northern parts of the basin and fostered the northern migration of planktonic foraminifera and coccoliths. The absence of sedimentary structures indicating significant wave activity or influence suggests deposition in relatively deep water, primarily below storm wave base. The abundance of pelagic organisms, coupled with widespread bottom-water anoxia, resulted in high TOC values. Persistent bottom-water anoxia is indicated by a lack of benthic foraminifers at most localities and the widespread occurrence of well-laminated, non-bioturbated sediments. Mixing of surface waters created major plankton kills. This introduced large amounts of organic matter into the deeper water column, creating an extensive anoxic zone. Bloch et al. (1999) present petrographic, chemical, mineralogical and isotopic data that indicate the early diagenesis of Colorado Group shales was dominated by two reactions: sulphate reduction, and methanogenesis. In addition, petrographic, isotopic and chemical data from clay minerals indicate that clay authigenesis was also an early diagenetic process. Late diagenesis (defined as mineral reactions that occur in response to a burial-induced increase in temperature and pressure) was characterized by quartz and feldspar dissolution, Fe-carbonate precipitation, and maturation of organic matter, as determined from petrographic observations, isotopic data and X-ray diffraction characteristics of clay minerals. Authigenic pyrite is a common constituent in the Colorado Group, ranging in abundance from <0.2 to 8.5 wt. % and Bloch et al. (1999) state that this is the primary evidence for the occurrence of early diagenetic sulphate reduction. This is also supported by their sulphur isotopic data from pyrite. Organic matter type and abundance, and benthic activity, are primary controls on the extent and rate of sulphate reduction within sediments. The Second White Specks (Favel), Morden, and First White Speckled (Niobrara) formations are characterized by high TOC and S values (generally >2 wt. % for each), and by Fe/S ratios greater than or equal to 1. These shales were deposited beneath a relatively deep, productive water column during transgressive periods, where bottom-water conditions were anoxic to dysoxic. Using the simplest approximation of the process of sulphate reduction, the rate at which this process occurs is dependent on the reactivity of organic matter and the availability of sulphate. These shales exhibit very large and consistent depletions in 34S in sulphur in pyrite, which is characteristic of condensed sections with low sedimentation rates and high, reactive TOC content (Bloch et al., 1999).

4. Previous Studies of the Metal Contents of Cretaceous Oil Shales Dunn (1990) conducted a lithogeochemistry study of Cretaceous stratigraphy in central Saskatchewan based on analyses from well cuttings. This provided information to a national program (Reichenbach, 1993) the purpose of which was to review black shales as a potential environmental hazard. From 56 well cuttings of the White Specks formations, Dunn (1990) found the following average metal values (all in parts per million (ppm)): Ag 0.4 Cd 4 Mn 307 Sb 3.5 Ti 110 As 22 Co 11 Mo 34 Se 11.7 V 121 B 23 Cr 18 Ni 68 Sr 170 W <1 Ba 76 Cu 50 P 820 Te 0.2 Zn 189 Bi 0.4 Ge 0.1 Pb 15 Th 5

(Gold, platinum group elements (PGE), uranium, rare earth elements (REE), and rare metals–among other elements–were not included in this study.) From the results of an extensive reconnaissance geochemical rock sampling and analytical program conducted in Cretaceous sedimentary rocks in northern Alberta (Dufresne et al., 2001), the Second White Specks Formation yielded locally anomalous concentrations of Au, Pt, Pd, Ag, Sb, As, Cu, Zn, Cd, Co, Ni, V, Mo, Fe, Mn, Ba, Ca, Br, Se, U, REE, Y, S and TOC. Elevated metal values were found to exhibit a positive correlation with TOC and with S and Fe. Highly anomalous concentrations of precious and base metals in the Second White Specks Formation occur in spatial association with the areas of increased bentonitic material. Pyrite is the principal sulphide (and possibly marcasite and/or greigite) and occurs almost exclusively as disseminated framboids (Dufresne et al., 2001).

Saskatchewan Geological Survey 6 Summary of Investigations 2016, Volume 2

A follow-up multiyear exploration program based on the Dufresne et al. (2001) study undertaken by DNI Metals Inc. led to the discovery of a number of areas of anomalous metal concentrations, notably including the Buckton deposit, a very large, low-grade, multi-element deposit. Eccles et al. (2013) produced an NI 43-101–compliant technical report on the deposit, which included an Indicated Mineral Resource for the Second White Specks Formation portion of the deposit of 65.329 million tonnes (Mt) grading (in ppm):

MoO3 100.4 La2O3 57.7 Tb2O3 1.3 Y2O3 54.9 Ni 142.9 Ce2O3 89.4 Dy2O3 7.8 (TREO) + Y 299.9 U3O8 29.1 Pr2O3 11.9 Ho2O3 1.6 Sc2O3 14.3 V2O5 1315.5 Nd2O3 45.8 Er2O3 4.3 ThO2 11.6 Zn 273.6 Sm2O3 9.2 Tm2O3 0.6 Li2CO3 298.7 Cu 74.4 Eu2O3 2.0 Yb2O3 4.1 Co 23.4 Gd2O3 8.7 Lu2O3 0.6

Their report also included an Inferred Mineral Resource of 923.168 million tonnes with similar grades. Fedikow et al. (1998) published a lithogeochemical database of over 600 Phanerozoic black shale samples from outcrop, well cuttings and core in Manitoba. The purpose of that study was to provide information for metallogenic and environmental studies. Samples of shale were taken from stratigraphic units ranging from Ordovician to Tertiary and included the oil shales of the Niobrara and Favel formations.

5. Project Methodology Core from five drillholes that were drilled by Questerre Energy Corporation in 2012 on the northwest flank of the Pasquia Hills were selected for sampling (Figure 2, Table 1). The cores are available for viewing and study at the Subsurface Geological Laboratory in Regina. The drillholes were spaced relatively equidistant, at 6 to 10 km apart, and all have available geological and geophysical downhole logs and TOC analyses. The oil shale sections with generally ≥5% TOC are relatively shallow in this area (10 to 50 m and locally to 100 m) and average about 30 m in thickness. The gamma ray and induction-resistivity logs display elevated profiles in the oil shale sections in all five holes. The formations are not identified in the drillhole logs and the oil shale intervals are collectively referred to as the White Specks. In a separate drill program (Thomas, 2013) in the same area as this study in Township 48, Range 11, the oil shale unit was identified as the Favel Formation, which is overlain by the Morden Formation and underlain by the Lower Colorado Group. The Morden Formation and Lower Colorado Group subcrop, respectively, to the south and north of the Favel Formation due to the northward-facing erosional slope. Four sections of 6.5 cm diameter core, each 1 m long, were sampled from each of the five drillholes, for a total of 20 samples (Table 2). Selection of the intervals to sample was based on high TOC content and an approximately equal- spaced distribution through the oil shale section in each hole. Some of the sampled intervals are displayed in Figures 4 to 7. Chips were taken by hand along the 1 m core length for each sample and placed in a plastic sample bag. A basic description was recorded. A magnet was passed thoroughly through the sample to remove any metallic material and rings were not worn by the samplers. The sample number was written on both sides of the sample bag and on a piece of flagging tape that was placed in the bag. The bag was sealed with tape and placed in a plastic pail that was delivered to the Saskatchewan Research Council Geoanalytical Laboratories in Saskatoon for multi-element analysis. The multi-element analyses were conducted using inductively coupled plasma–optical emission spectroscopy (ICP- OES) with separate partial and total digestion sample runs. The gold, platinum and palladium analyses were completed using fire assay and an ICP-OES finish. The complete laboratory procedures, including sample preparation, detection limits and quality control, as well as the analytical results are described in Data File 41.

Saskatchewan Geological Survey 7 Summary of Investigations 2016, Volume 2

Table 1 – Descriptions of the five drillholes that were sampled in this study.

UTM UTM >5% Drillhole Name NTS_502 Formation Cored Interval Oil Shale Interval SMDI4 83_13_E1 83_13_N1 TOC3 Questerre Arborfield 602839 5878412 63E03 Favel 20.5 - 161.5 m 95 - 128 m (33 m) 26 m 5311 16-12-47-11 Questerre Arborfield 611742 5888399 63E03 Favel 32.5 - 110.0 m 46 - 80 m (34 m) 34 m 5312 2-13-48-10 Questerre Arborfield 602235 5884953 63E03 Favel 8.0 - 99.0 m 32 - 66 m (34 m) 28 m 5313 2-1-48-11 Questerre Arborfield 601022 5890081 63E03 Favel 7.0 - 68.5 m 11 - 39 m (28 m) 28 m 5320 4-24-48-11 Questerre Arborfield 594552 5883154 63E04 Favel 7.2 - 89.0 m 33 - 65 m (32 m) 32 m 5315 1-31-47-11 1 UTM coordinates, in NAD83, Zone 13; E = easting, N = northing 2 National Topographic Survey 1:50 000-scale map sheet 3 Total organic carbon values are from the core analyses from the original drill program 4 Saskatchewan Mineral Deposit Index file number

Table 2 – Summary of the samples collected for this study.

Drillhole Name and Oil Shale Sample Number Sample Interval TOC (%)* Sample Description Interval Questerre Arborfield 16-12-47-11 QA 16-12-47-11-1 98 - 99 m 9.61 Black shale – some fissility Oil shale interval 95 to 128 m QA 16-12-47-11-2 108 - 109 m 8.78 Black shale – moderately fissile QA 16-12-47-11-3 118 - 119 m 11.83 Black shale – calcareous with white specks and weakly fissile QA 16-12-47-11-4 124 - 125 m 9.34 Black shale – moderately fissile

Questerre Arborfield 2-13-48-10 QA 2-13-48-10-1 50 - 51 m 10.34 Black shale – calcareous Oil shale interval 46 to 80 m QA 2-13-48-10-2 59 - 60 m 9.07 Black shale – calcareous with white specks QA 2-13-48-10-3 68 - 69 m 15.60 Black shale – calcareous with white specks QA 2-13-48-10-4 76 - 77 m 9.18 Black shale – fissile, with white specks and fine pyrite

Questerre Arborfield 2-1-48-11 QA 2-1-48-11-1 38 - 39 m 9.93 Dark grey shale Oil shale interval 32 to 66 m QA 2-1-48-11-2 46 - 47 m 8.27 Black shale – calcareous QA 2-1-48-11-3 54 - 55 m 9.36 Black shale – calcareous, small white spots, fine pyrite, moderately fissile QA 2-1-48-11-4 60 - 61 m 8.38 Black shale – calcareous, small white spots

Questerre Arborfield 4-24-48-11 QA 4-24-48-11-1 15 - 16 m 8.77 Black shale – calcareous Oil shale interval 11 to 39 m QA 4-24-48-11-2 19 - 20 m 8.44 Black shale – calcareous QA 4-24-48-11-3 27 - 28 m 17.24 Dark grey shale – calcareous with white spots QA 4-24-48-11-4 34 - 35 m 10.27 Black shale – calcareous, fissile

Questerre Arborfield 1-31-47-11 QA 1-31-47-11-1 34 - 35 m 8.04 Black shale – moderately fissile Oil shale interval 33 to 65 m QA 1-31-47-11-2 45 - 46 m 7.61 Dark grey shale – calcareous, moderately fissile QA 1-31-47-11-3 58 - 59 m 7.08 Dark grey shale – calcareous, friable QA 1-31-47-11-4 61 - 62 m 8.79 Black shale – calcareous, moderately fissile * Total organic carbon values are taken from the original drill program results and are the average of spot samples taken near the top and bottom of the drilled intervals during the drill program.

Saskatchewan Geological Survey 8 Summary of Investigations 2016, Volume 2

Figure 4 – The complete oil shale core section of drillhole Questerre Arborfield (QA) 4-24-48-11 displayed for perspective with the sample intervals marked by yellow tags.

Figure 5 – A portion of the 27 to 28 m sample interval in drillhole QA 4-24-48- 11: medium to dark grey, calcareous, white speckled shale. The white calcareous spots and streaks are the result of fossil debris and are characteristic of these “White Speckled” shales.

Saskatchewan Geological Survey 9 Summary of Investigations 2016, Volume 2

Figure 6 – A portion of the 34 to 35 m sample interval in drillhole QA 4-24-48-11: dark grey to black, calcareous, fissile shale.

Figure 7 – Sample interval 76 to 77 m in drillhole QA 2-13-48-10, within a section of dark grey to black, fissile and friable, calcareous shale. Base of tape measure is 6.5 cm long.

6. Discussion of Analytical Results The complete analytical results are tabulated in Data File 41, which is referenced at the beginning of this paper and is accessible on the Ministry of the Economy website at http://www.publications.gov.sk.ca/details.cfm?p=83163. “Metalliferous” for this study refers to metals with an arithmetic mean (average) value for all 20 samples that meets or exceeds the USGS standard (Huyck, 1990; see section on ‘Geochemical Standard for Metalliferous Black Shales’). The arithmetic mean for each element for all 20 core samples is summarized in Table 3, which also indicates those concentrations that qualify as metalliferous. A more detailed summary of the metalliferous elements and those elements with individual sample analyses that meet or exceed the USGS standard is provided in Table 4.

Saskatchewan Geological Survey 10 Summary of Investigations 2016, Volume 2

Table 3 – Summary of the arithmetic mean geochemical values of the 20 samples, based on ICP-OES total and partial digestion, and fire assay–ICP-OES analyses. Metalliferous values are in bold font and yellow highlight.

Arithmetic Mean Metal Values of the 20 samples (ICP-OES total digestion)

Ag (ppm) Ba (ppm) Be (ppm) Cd (ppm) Co (ppm) Cr (ppm) Cu (ppm) Fe2O3 (%) Ga (ppm) Hf (ppm) Li (ppm) MnO (%) 1.4 499 1.1 8 16 92 94 4.42 10 <1 49 0.04

Mo (ppm) Nb (ppm) Ni (ppm) P2O5 (%) Pb (ppm) S (ppm) Sn (ppm) Sr (ppm) Ta (ppm) Th (ppm) TiO2 (%) U (ppm) 73 13 114 0.28 23 32620 1 248 <1 8 0.38 20 V (ppm) W (ppm) Zn (ppm) Zr (ppm) Ce (ppm) Dy (ppm) Er (ppm) Eu (ppm) Gd (ppm) Ho (ppm) La (ppm) Nd (ppm) 632 1 276 99 47 3.0 1.9 1.0 5 <1 29 24

Pr (ppm) Sm (ppm) Tb (ppm) Yb (ppm) Sc (ppm) Y (ppm) Al2O3 (%) CaO (%) K2O (%) MgO (%) Na2O (%) 4 5 <1 2.3 7 25 10.4 17.8 2.17 0.94 0.71

Arithmetic Mean Metal Values of the 20 samples (ICP-OES partial digestion) Ag (ppm) As (ppm) Bi (ppm) Co (ppm) Cu (ppm) Ge (ppm) Hg (ppm) Mo (ppm) Ni (ppm) Pb (ppm) S (ppm) Sb (ppm) 1.1 35 1 14 91 1 <1 61 99 13 26940 1.6 Se (ppm) Te (ppm) U (ppm) V (ppm) Zn (ppm) 16 <1 15 245 235

Arithmetic Mean Metal Values of the 20 samples (Fire Assay–ICP-OES) Au (ppb) Pd (ppb) Pt (ppb) 45 3 2 ICP-OES: inductively coupled plasma–optical emission spectroscopy analysis ppm: parts per million ppb: parts per billion %: weight percent Mean values rounded to the nearest relevant whole or decimal value. Less than detection limit is treated as 0 in calculation. Metalliferous values compared to the USGS standard are in bold font and highlighted. Note: Conversion factors for MnO to Mn (0.775) with 0.084% MnO equivalent and P2O5 to P (0.436) with 0.22% P2O5 equivalent for the USGS standard. High Fe2O3 and S values in bold font are not considered metalliferous, but are likely related to contained pyrite and sulphates.

Saskatchewan Geological Survey 11 Summary of Investigations 2016, Volume 2

Table 4 – Summary of the metalliferous elements and other elements with individual analyses that meet or exceed the USGS standard. (Empty rows indicate where the element was not included in the respective analysis.)

Metalliferous Elements

Element Ag (ppm) Au (ppb) P2O5 (%) Se (ppm) Sr (ppm) V (ppm)* Zn (ppm) USGS Standard 0.262 5.6 0.22 9.8 150.2 320 128.2 PD Sample No. 20 11 7 19 PD Mean Value 1.1 16 245 235 PD Low Value 0.8 <1 85 112 PD High Value 1.6 48 476 428

TD Sample No. 20 14 17 12 20 TD Mean Value 1.4 0.28 248 632 276 TD Low Value 1.1 0.17 118 157 140 TD High Value 2.0 0.72 598 1090 430

FA Sample No. 19 FA Mean Value 45 FA Low Value <2 FA High Value 129

Other Elements with Samples that Meet or Exceed the USGS Standard Element Ba (ppm) Cd (ppm) Cr (ppm) Cu (ppm) Li (ppm) USGS Standard 694 10 132.8 120.4 56.2 PD Sample No. 5 PD Mean Value 91 PD Low Value 42 PD High Value 149

TD Sample No. 2 8 4 6 7 TD Mean Value 499 8 92 94 49 TD Low Value 60 3 23 47 11 TD High Value 1130 17 180 153 97 ppm: parts per million ppb: parts per billion %: weight percent PD: partial digestion with inductively coupled plasma–optical emission spectroscopy (ICP-OES) analysis TD: total digestion ICP-OES analysis FA: fire assay + ICP-OES analysis Sample No.: number of samples out of 20 whose metal concentrations meet or exceed the USGS standard value. Mean Value: arithmetic mean of all 20 sample analyses. Low Value: lowest concentration out of 20 samples. High Value: highest concentration out of 20 samples. *Note: V is not considered metalliferous for partial digestion but is for total digestion. Partial digestion values are displayed for comparison. a) Partial Digestion ICP-OES Results Partial digestion using aqua regia dissolves sulphides and some oxides. Seventeen elements were included in the analysis, of which Ag, Se and Zn were found to be metalliferous (Tables 3 and 4). All of the Ag analyses exceed the USGS standard of 0.262 ppm, with a mean value of 1.1 ppm (4.2X) and a high value of 1.6 ppm. For Zn, 19 of the 20 analyses exceed the standard of 128.2 ppm, with a mean value for the 20 samples of 235 ppm and a high value of 428 ppm. All 20 analyses for S were high, but not considered metalliferous, with a mean content of 26 940 ppm (2.694%). This was expected and mainly, if not exclusively, due to the contained fine-grained pyrite.

Saskatchewan Geological Survey 12 Summary of Investigations 2016, Volume 2

Individual analyses of Cu and V exceed their respective standards (Table 4) but their arithmetic means for all 20 samples do not and these elements are therefore not considered to be metalliferous for this study. The distribution of the mean values (average of all four samples) per hole of a few selected elements (Ag, Zn, Cu, V) is quite uniform (Figure 8), displaying little variation between the drillholes. These metal concentrations are attributed to absorption by organic matter from seawater and concentration in minerals during diagenesis in the reduced, anoxic sediments. This interpretation is based on the uniformity and levels of the metal values and other interpretations of metalliferous black shales in the published literature (Dumoulin et al., 2011; Lehmann et al., 2016).

Figure 8 – Distribution of some mean geochemical values (Ag (ppm), Zn (ppm), Cu (ppm), V (ppm), TOC (wt. %)) from the core samples in the five drillholes. Silver, Zn, Cu and V are from partial digestion and ICP-OES analysis; TOC analyses are from the original drill program. Base map with township grid, towns and drillholes is from the Geological Atlas of Saskatchewan, Ministry of the Economy website. Township grid numbers in blue are Township-Range-West of the Second Meridian.

b) Total Digestion ICP-OES Results Total digestion, as the name implies, dissolves every mineral including silicates, releasing all contained metals for analysis. A total of 38 elements and 9 oxides were included in this analysis. Of these, Ag, P2O5, Sr, V and Zn were found to be metalliferous (Tables 3 and 4). Silver, Co, Cu, Mo, Ni, Pb, U, V and Zn were included in both the partial and total digestion analyses. The total digestion metal values, with the exception of V, are only modestly higher than the comparative partial digestion values (Table 3). This indicates that these metals are largely held by sulphides and/or by readily digested oxides. The total digestion mean value of 632 ppm for V is substantially higher than the partial digestion mean value of 245 ppm V, indicating that much of this element is held in minerals, possibly oxides or silicates that are not dissolved by aqua regia. The Sr is likely accommodated within carbonate and/or sulphate minerals. Barium, Cd, Cr, Cu and Li have individual analyses that exceed their respective standards (Table 4) but their means for all 20 samples do not, and these elements are therefore not considered to be metalliferous. Figure 9 displays the mean values of the metalliferous elements for the five drillholes. The distribution of Ag, Zn, P2O5, Sr and V are relatively consistent between the holes, displaying little variation. These values are attributed to absorption of metals by organic matter from seawater and further concentration in minerals during diagenesis in the reduced, anoxic sediments. This interpretation is based on the uniformity and levels of the metal values and other interpretations of metalliferous black shales in the published literature (Dumoulin et al., 2011; Lehmann et al., 2016).

Saskatchewan Geological Survey 13 Summary of Investigations 2016, Volume 2

Figure 9 – Distribution of the mean values for metalliferous elements (Ag (ppm), Zn (ppm), P2O5 (wt. %), Sr (ppm), V (ppm)) from the core samples in the five drillholes, from total digestion ICP-OES analysis. Base map with township grid, towns and drillholes is from the Geological Atlas of Saskatchewan, Ministry of the Economy website. Township grid numbers in blue are Township-Range-West of the Second Meridian.

Sulphur has a mean value of 32 620 ppm, with a range of values from 20 500 ppm to 46 600 ppm. The mean values for this element between the five drillholes are very consistent, with a range from 31 280 ppm to 35 800 ppm. This sulphur content is significantly higher than the 26 940 ppm mean from the partial digestion analyses, and indicates that there is likely a sulphate source for the extra sulphur in addition to the pyrite. Gypsum and ammonium sulphate have been noted in the previous oil shale descriptions. Fe2O3 has a mean content of 4.42 wt. % and a range in individual values from 1.92 to 6.37 wt. % (Table 5). The mean values for Fe2O3 between the five holes were consistent, with a range from 3.87 to 5.04 wt. %. There is a good correlation between the Fe2O3 and S values, indicating that most of the Fe is associated with pyrite.

The results of all the major oxide analyses are summarized in Table 5. There is good consistency in the K2O, MgO and Na2O values, both within individual drillholes and between the holes. The Al2O3 results display a somewhat more variable distribution of values, both within and between the holes, which is attributed to variations in the clay content. By contrast, the CaO values are highly variable both within the holes and between the holes. This is directly related to the highly variable content of calcareous fossil material in the samples.

Table 5 – Major oxide analyses from total digestion and ICP-OES analysis (values in wt. %). (Note: SiO2 was not included in the analyses.)

Major Oxide Arithmetic Mean Range of Sample Range of Mean Values Value Values for Drillholes

Al2O3 10.4% 2.80% - 15.5% 8.98% - 12.53% CaO 17.8% 0.78% - 49.1% 8.15% - 23.75%

Fe2O3 4.42% 1.92% - 6.37% 3.87% - 5.04%

K2O 2.17% 0.82% - 3.28% 1.83% - 2.54% MgO 0.94% 0.51% - 1.37% 0.83% - 1.05%

Na2O 0.71% 0.40% - 1.84% 0.62% - 0.93%

Saskatchewan Geological Survey 14 Summary of Investigations 2016, Volume 2

c) Fire Assay–ICP-OES Results Gold values are uniformly highly anomalous, with 19 of the 20 analyses exceeding the USGS standard of 5.6 ppb Au (Table 4), with a mean value for all 20 samples of 45 ppb (8X) and a high value of 129 ppb (23X). The mean values for each drillhole are not uniform and display a regional zonation, albeit based on a limited sample group (Figure 10). The three northeast drillholes range from 16 to 26 ppb Au, with a mean value of 21.3 ppb Au, whereas the western drillhole has a mean value of 103 ppb Au and the southern drillhole has a mean value of 58 ppb Au. Based on interpretations of metalliferous black shales in the published literature (Hulbert et al., 1992; Loukola-Ruskeeniemi and Heino, 1996; Dumoulin et al., 2011), the highly anomalous gold values, and the apparent regional trend in gold, a low-temperature hydrothermal source of the gold to the west or west-southwest at the time of deposition is indicated. The Geological Map of Saskatchewan (Macdonald and Slimmon, 1999) displays the interpreted projection of the Tabbernor Fault Zone (TFZ) (Figure 1) extending near or through the project area. The TFZ is a long-lived, north- trending, crustal-scale structure, typically consisting of a series of subparallel faults, which could have been the conduit for the hydrothermal fluids. There is no apparent hydrothermal alteration, based on visual examination of the core and on the results of the major oxide analyses (Table 5), particularly in the western drillholes with the higher values, to indicate an immediate hydrothermal source. A source to the west of the western drillhole is therefore postulated. This apparent zonation, however, could also be an artifact of the limited number of samples in each hole in the study. Perhaps if the full oil shale sections were sampled in each hole the gold distribution would be different.

Figure 10 – Distribution of the arithmetic mean gold values for each drillhole (values in ppb). Base map with township grid, towns and drillholes is from the Geological Atlas of Saskatchewan, Ministry of the Economy website. Township grid numbers in blue are Township-Range-West of the Second Meridian.

By contrast, the Pt and Pd values display no apparent enrichment and are consistent between all of the drillholes. The mean value for Pt for the 20 samples is 2 ppb, with a high value of 4 ppb (Table 3). The mean value for Pd is 3 ppb, with a high value of 8 ppb (Table 3).

7. Acknowledgments Geological assistant Ian Folkerson provided enthusiastic assistance in the sampling program (Figure 4). Arden Marsh was very helpful in providing information to access the records for the drillholes available at the Subsurface Geological Laboratory (SGL). The administration and core handling personnel at the SGL provided quick and efficient

Saskatchewan Geological Survey 15 Summary of Investigations 2016, Volume 2

service. Discussions and some reference information from Charles Normand were beneficial to this project. Ralf Maxeiner and Ken Ashton are thanked for providing thorough reviews and comments that greatly improved this manuscript. Production editing by Heather Brown was instrumental in the publication of this paper.

8. References Beck, L.S. (1974): Geological Investigations in the Pasquia Hills Area; Saskatchewan Geological Survey, Department of Mineral Resources, Report No. 158, 16p. Bloch, J.D., Schröder-Adams, C.J., Leckie, D.A., Craig, J. and McIntyre, D.J. (1999): Sedimentology, micropaleontology, geochemistry, and hydrocarbon potential of shale of the Cretaceous Lower Colorado Group in western Canada; Geological Survey of Canada, Bulletin 531, 185p. Bloch, J.D., Schröder-Adams, C.J. and Leckie, D.A. (2002): The petrology of Late Cretaceous Colorado Group shales from the Pasquia Hills, east-central Saskatchewan: Preliminary results; in Summary of Investigations 2002, Volume 1, Saskatchewan Geological Survey, Saskatchewan Industry and Resources, Miscellaneous Report 2002-4.1, p.126-133. Christopher, J.E. and Yurkowski, M. (2005): The Upper Cretaceous (Turonian) Second White Specks Formation of eastern Saskatchewan; in Summary of Investigations 2005, Volume 1, Saskatchewan Geological Survey, Saskatchewan Industry and Resources, Miscellaneous Report 2005-4.1, Paper A-18, 12p. Christopher, J.E., Yurkowski, M., Nicolas, M. and Bamburak, J. (2006): The Upper Cretaceous (Turonian-Santonian) Carlile Formation of eastern southern Saskatchewan, and the correlative Morden and Boyne members of southwestern Manitoba; in Summary of Investigations 2006, Volume 1, Saskatchewan Geological Survey, Saskatchewan Industry and Resources, Miscellaneous Report 2006-4.1, Paper A-13, 16p. Continental Precious Minerals Inc. (2014): Press release, February 6, 2014, Viken project mineral resource; http://czqminerals.com/wp-content/uploads/2014/02/Viken-PEA-Press-Release-Final-Feb-5-2014-545pmEST.pdf [accessed 29 June 2016]. Dufresne, M.B., Eccles, D.R. and Leckie, D.A. (2001): The Geological and Geochemical Setting of the Mid-Cretaceous Shaftesbury Formation and Other Colorado Group Sedimentary Units in Northern Alberta; Alberta Geological Survey, Alberta Energy and Utilities Board, Special Report 09, 654p. Dumoulin, J.A., Slack, J.F., Whalen, M.T. and Harris, A.G. (2011): Depositional setting and geochemistry of phosphorites and metalliferous black shales in the Carboniferous-Permian Lisburne Group, northern Alaska; in Studies by the U.S. Geological Survey in Alaska, 2008-2009, Dumoulin, J.A. and Galloway, J.P. (eds.), United States Geological Survey, Professional Paper 1776-C, 64p. Dunn, C.E. (1990): Lithogeochemical study of the Cretaceous in central Saskatchewan – Preliminary report; in Summary of Investigations 1990, Saskatchewan Geological Survey, Saskatchewan Energy and Mines, Miscellaneous Report 90-4, p.193-197. Eccles, R., Nicholls, S., McMillan, K. and Dufresne, M. (2013): National Instrument 43-101 Technical Report, Updated and Expanded Mineral Resource Estimate for the Buckton Zone, SBH Property, Northeast Alberta; prepared for DNI Metals Inc., 137p., available on www.sedar.com. Fedikow, M.A.F., Bezys, R.K., Bamburak, J.D., Conley, G.G. and Garrett, R.G. (1998): Geochemical database for Phanerozoic black shales in Manitoba; Manitoba Geological Services, Manitoba Energy and Mines, Open File Report OF98-2, 124p. Hulbert, L.J., Grégoire, D.C., Paktunc, D. and Carne, R.C. (1992): Sedimentary nickel, zinc, and platinum-group-element mineralization in Devonian black shales at the Nick property, Yukon, Canada: A new deposit type; Exploration and Mining Geology, v.1, no.1, p.39-62. Huyck, H.L.O. (1990): When is a metalliferous black shale not a black shale?; in Metalliferous Black Shales and Related Ore Deposits – Proceedings, 1989 United States Working Group Meeting, International Geological Correlation Program Project 254, Grauch, R.I. and Huyck, H.L.O. (eds.), United States Geological Survey, Circular 1058, p.42-56. Large, R. (2012): Future potential for metal resources from black shales: Ni, Mo, Zn, Cu, U, V, Ag, Au, PGE; University of Tasmania, unpublished presentation, 43p. https://www.aig.org.au/wp-content/uploads/2012/12/Ross-Large-Future-Potential- for-Metal-Resources-from-Black-Shales.pdf [accessed 13 April 2016].

Saskatchewan Geological Survey 16 Summary of Investigations 2016, Volume 2

Lehmann, B., Frei, R., Xu, L. and Mao, J. (2016): Early Cambrian black shale-hosted Mo-Ni and V mineralization on the rifted margin of the Yangtze Platform, China: Reconnasissance chromium isotope data and a refined metallogenic model; Economic Geology, v.111, no.1, p.89-103. Loukola-Ruskeeniemi, K. and Heino, T. (1996): Geochemistry and genesis of the black shale-hosted Ni-Cu-Zn deposit at Talvivaara, Finland; Economic Geology, v.91, no.1, p.80-110. Macauley, G. (1984): Cretaceous oil shale potential in Saskatchewan; in Oil and Gas in Saskatchewan 1984, Lorsong, J.A. and Wilson, M.A. (eds.), Saskatchewan Geological Society, Special Publication No. 7, p.255-269. Macdonald, R. and Slimmon, W.L. (compilers) (1999): Geological Map of Saskatchewan, 1999 Edition; Saskatchewan Industry and Resources, 1:1 000 000 scale map. Reichenbach, I. (1993): Black shale as an environmental hazard: a review of black shales in Canada; Geological Survey of Canada, Open File 2697, 62p. Schröder-Adams, C.J., Leckie, D.A., Craig, J. and Bloch, J. (1999): Upper Cretaceous Colorado Group in the Pasquia Hills, northeastern Saskatchewan: a multidisciplinary study in progress; in Summary of Investigations 1999, Volume 1, Saskatchewan Geological Survey, Saskatchewan Energy and Mines, Miscellaneous Report 99-4.1, p.52-56. Thomas, M. (2013): Pasquia Hills oil shale project core test hole drilling, February, 2013, east-central Saskatchewan (Tsp. 47-50, Rge. 9-12, W2M), Geological/Drilling Field Report, 8p.; Transaction Arborfield 9-5-48-11, License Number 13A077; http://www.dwd.gov.sk.ca/pages/basepages/main.aspx.

Saskatchewan Geological Survey 17 Summary of Investigations 2016, Volume 2